CHEST
OUTLINE
PATTERN RECOGNITION OF CHEST PATHOLOGY (X-RAY)
• LUNG
Increased density
Decreased density
• MEDIASTINUM
• PLEURA & EXTRATHORACIC
TUMOUR vs INFECTION
Increased density
(opacities)
• Alveolar
(consolidation)
• Interstitial
• Atelectasis
(collapse)
• Nodule or mass
Decreased density
(lucencies)
• Cavitation
• Cyst
• Emphysema
LUNG ABNORMALITIES ON CHEST X-RAY
INCREASED DENSITY
ALVEOLAR (CONSOLIDATION)
• Results from pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor
cells) or other substances.
• General features on chest x-ray show ill-defined, fluffy, cottonwool-like appearance of
airspace opacification causing obscuration of pulmonary vessels and air bronchograms.
• Air bronchogram
air-filled bronchi (dark)
being made visible by the
opacification of surrounding
alveoli (grey/white).
LOBAR CONSOLIDATION
• Results from disease that starts in the
periphery and spreads from one
alveolus to another through the pores
of Kohn.
• At the borders of the disease some
alveoli will be involved, while others
are not, creating ill-defined borders.
• As the disease reaches a fissure, this
will result in a sharp delineation, since
consolidation will not cross a fissure
(limited by visceral pleura).
BULGING FISSURE SIGN
• Refers to lobar consolidation where
the affected portion of the lung is
expanded causing displacement of
the adjacent fissure.
• Classically, it has been described
in right upper lobe
(RUL) consolidation secondary
to Klebsiella pneumonia.
• Other causes include:
• Infective (Strep. pneumoniae,
Pseudomonas aeruginosa, Staph.
aureus)
• Lung adenocarcinoma
• Lung abscess
• Pulmonary haemorrhage
DIFFUSE CONSOLIDATION
• Progression of multifocal opacities
that coalesce produce diffuse
consolidation.
• Does not cross fissure.
BATWING CONSOLIDATION
• Bilateral perihilar distribution of
consolidation.
• The sparing of the periphery of
the lung is attributed to a better
lymphatic drainage in this area.
• Most typical of pulmonary
oedema, both cardiogenic and
non-cardiogenic.
• Sometimes it is seen in
pneumonias.
ATELECTASIS (COLLAPSE)
• Result of loss of air in a lung or part of the lung with subsequent volume loss
due to airway obstruction or compression of the lung by pleural fluid or a
pneumothorax.
• General features on chest x-ray:
• Sharply-defined opacity obscuring vessels without air-bronchogram.
• Volume loss resulting in displacement of diaphragm, fissures, hila or
mediastinum.
Passive
Loss of intrapleural
negative pressure
causing lung to be no
longer held against
chest wall.
Obstructive
Occurs as a result of
complete obstruction
of an airway.
No new air can enter,
any air that is already
there is eventually
absorbed into the
pulmonary capillary
system.
Compressive atelectasis
• occurs as a result of any thoracic
space-occupying lesion compressing
the lung and forcing air out of the
alveoli
Cicatrization atelectasis
• occurs as a result of scarring or
fibrosis that reduces lung expansion
• common aetiologies
include granulomatous
disease, necrotizing
pneumonia and radiation fibrosis
Right upper lobe collapse
• increased density in the upper
medial aspect of the right
hemithorax
• elevation and/or superior bowing
of the horizontal fissure
• loss of the normal right medial
cardio-mediastinal contour
• elevation of the right hilum
• rotation of the bronchus
intermedius laterally, appearing
more horizontal than usual
• hyperinflation of the right middle
and lower lobe result in increased
translucency of the mid and lower
parts of the right lung
• right juxtaphrenic peak (Kattan sign)
GOLDEN S SIGN
• Typically seen with right upper lobe
collapse.
• Created by a central mass
obstructing the upper lobe bronchus
and should raise suspicion of a
primary bronchogenic carcinoma.
• Can also be caused by other central
masses, such as metastasis, primary
mediastinal tumour, or enlarged
lymph nodes.
Right middle lobe collapse
• right mid to lower zone air
space opacification (which can
be subtle)
• the normal horizontal fissure is
no longer visible (as it rotates
inferiorly rendering it non-
tangential to the x-ray beam)
• obscuration of the right heart
border
• lateral projection: a triangular
opacity in the anterior aspect
of the chest overlying the
cardiac shadow.
Right lower lobe collapse
• triangular opacity at the right lower
zone (usually medially) with the
apex pointing towards the right
hilum
• obscuration of the medial aspect of
the dome of right hemidiaphragm
• inferior displacement of the right
hilum
• descending interlobar pulmonary
artery is not visible
• preservation of a clear right heart
border, which is contacted by the
right middle lobe
• inferior displacement of
the horizontal fissure
Left upper lobe collapse
• Collapsed left upper lobe appears as a
hazy or veiling opacity extending out from
the left hilum and fading out inferiorly
• Obscuration of parts of the normal
cardiomediastinal contour particularly
where the lingular segments abuts the left
heart border
• Luftsichel sign the hyperexpanded superior
segment of the left lower lobe insinuates
between the left upper lobe and the
superior mediastinum, sharply silhouetting
the aortic arch resulting in a sickle-shaped
lucency medially
• The left hilum is drawn upwards
Left lower lobe collapse
• triangular left lower zone opacification
(usually medially, retrocardiac) with the
apex pointing towards the left hilum
• edge of the collapsed lung may create a
'double cardiac contour'
• inferior displacement of the left hilum
• Flat waist sign: flattening of the left heart
border
• obscuration of the left hemidiaphragm
• obscuration of the descending aorta
• preservation of a clear left heart border,
which is contacted by the lingular segments
of the left upper lobe
• inferior displacement of the oblique fissure
• descending interlobar pulmonary artery is
not visible
Plate atelectasis
• Focal area of subsegmental
atelectasis that has a linear shape.
• May appear to be horizontal, oblique
or perpendicular line of 1-3 mm in
thickness.
• Frequently seen in patients in ICU due
to poor ventilation and postoperative
patients.
• In most cases these findings have no
clinical significance and are seen in
smokers and elderly.
SILHOUETTE SIGN
• Pathological loss of two adjacent
structures differentiation (i.e. lung
and mediastinal border).
• It denotes that a mediastinal
border can only be obscured by
pathology which is in direct
anatomical contact.
• Useful in localising areas of
airspace opacities, atelectasis or
mass within the lung.
Loss of silhouette:
• right paratracheal stripe: right upper
lobe
• right heart border: right middle lobe
or medial right lower lobe
• right hemidiaphragm: right lower
lobe
• aortic knuckle: left upper lobe
• left heart border: lingular segments
of the left upper lobe
• left hemidiaphragm or descending
aorta: left lower lobe
INTERSTITIAL OPACITY
• Reticular opacities or small nodules due
to involvement of the supporting tissue
of the lung parenchyma (interstitium).
• Results from thickening of any of the
interstitial compartments by blood,
water, tumor, cells, fibrous disease or
any combination thereof.
• Can be reticular, reticulonodular, or
linear where the predominant pattern
is a result of the underlying
pathological process.
Reticular interstitial opacity
• Complex network of
curvilinear opacities that
usually involved the lung
diffusely.
• Can be subdivided by their
size based on the size of the
lucent spaces created by the
intersection of lines.
• Fine "ground-glass" (1-2 mm):
seen in processes that thicken
the pulmonary interstitium to
produce a fine network of lines,
e.g. interstitial pulmonary oedema
• Medium "honeycombing" (3-10
mm): commonly seen in pulmonary
fibrosis with involvement of the
parenchymal and peripheral
interstitium
• Coarse (>10 mm): cystic spaces
caused by parenchymal destruction,
e.g. usual interstitial pneumonia,
pulmonary sarcoidosis, pulmonary
Langerhans cell histiocytosis.
Reticulonodular interstitial opacity
• Overlap of reticular shadows or by the
presence of reticular shadowing
and pulmonary nodules.
• Relatively common appearance on
a chest radiograph, very few diseases
are confirmed to show this pattern
pathologically:
 silicosis
 pulmonary sarcoidosis
 berylliosis
 lymphangitic carcinomatosis
 hepatopulmonary syndrome -
basal
 pneumocystis pneumonia
 bronchocentric granulomatosis
 pulmonary Langerhans cell
histiocystosis
 lymphocytic interstitial pneumonitis
 Erdheim-Chester disease
Linear interstitial opacity
• Seen in processes that thicken the axial (bronchovascular) interstitium or the
peripheral pulmonary interstitium.
• Axial: diffuse thickening along the bronchovascular tree seen as parallel opacities
radiating from the hila (seen transversely) or peribronchial cuffing (seen en face).
• Peripheral: thickening of the peripheral interstitium (either medially or laterally)
produces Kerley lines.
• Axial interstitial thickening is difficult to distinguish from airways disease that result
in bronchial wall thickening, (e.g. bronchiectasis, asthma) and most often seen
in interstitial pulmonary oedema.
Kerley lines (septal lines)
• Prominent interlobular
septa in the pulmonary
interstitium because of
lymphatic engorgement or
oedema of the connective
tissues of the interlobular
septa.
• Usually occur when
pulmonary capillary wedge
pressure reaches 20-25
mmHg.
Causes
• pulmonary oedema
• neoplasm
• lymphangitic spread of cancer
• breast cancer
• colon cancer
• stomach cancer
• pancreatic cancer
• lung cancer
• lymphoma
• pulmonary lymphoma
• pneumonia
• viral pneumonia
• mycoplasma pneumonia
• Pneumocystis pneumonia
• interstitial pulmonary fibrosis
• pneumoconiosis
• sarcoidosis
Kerley A
• 2-6 cm long oblique lines that
are <1 mm thick and course
towards the hila.
• Represents thickening of the
interlobular septa that contain
lymphatic connections between
the perivenous and
bronchoarterial lymphatics deep
within the lung parenchyma.
• On chest radiographs they are
seen to cross normal vascular
markings and extend radially
from the hilum to the upper lobes.
Kerley B
• Thin lines 1-2 cm in length in
the periphery of the lung(s).
• Represent thickened subpleural
interlobular septa and are
usually seen at the lung bases.
• Perpendicular to the pleural
surface and extend out to it.
*Kerley D lines are exactly the
same as Kerley B lines, except that
they are seen on lateral chest
radiographs in the retrosternal air
gap.
Kerley C
• short lines which do not
reach the pleura and do not
course radially away from
the hila (neither A nor B).
NODULES OR MASSES
Suggested risk factors to consider
include older age, heavy smoking,
irregular or spiculated margins, and
upper lobe location.
• A discrete, well-
marginated, rounded
opacity less than or equal
to 3 cm in diameter.
• Lesions smaller than 3 cm
are most commonly benign
granulomas, while lesions
larger than 3 cm are
treated as malignancies
until proven otherwise and
are called masses.
Metastases
• Typically appear as
peripheral, rounded nodules
of variable size, scattered
throughout both lungs
predominantly lower lobes
and subpleural.
Mucoid impaction
• Can mimic the appearance of
lung nodules or a mass.
• Commonly seen in patients
with bronchiectasis, as in cystic
fibrosis (CF), allergic
bronchopulmonary
aspergillosis (ABPA) and
bronchial atresia.
• ‘Finger-in-glove’ appearance:
mucus in dilated bronchi looks
like fingers in glove.
DECREASED DENSITY
Lucency without a
visible wall.
Cavity
• Frequently arise within a
mass or an area of
consolidation as a result of
necrosis.
Monod sign
• Gas that surrounds a
mycetoma (most commonly
an aspergilloma) in a pre-
existing pulmonary cavity.
• Gas around the mycetoma is
often crescent-shaped and
hence, the term air crescent
sign is used interchangeably.
Pneumatocele
• Majority of pneumatoceles occur
as a result of pneumonia, most
common causative agents being S.
aureus.
Bulla
• Focal regions of emphysema with
no discernible wall which measure
more than 1 or 2 cm in diameter.
• Often subpleural in location and
are typically larger in the apices
Emphysema
• Abnormal permanent enlargement
of the airspaces distal to the
terminal bronchioles accompanied
by destruction of the alveolar wall
and without obvious fibrosis.
• Chest x-ray does not image
emphysema directly, but indirect
signs
• hyperinflation
• paucity of blood vessels
• pulmonary arterial hypertension
features (pruning of peripheral
vessels, increased calibre of
central arteries, right ventricular
enlargement)
MEDIASTINUM
Mediastinal division
• Superior: Above a line drawn from
lower border of T4 to sternal angle.
• Anterior: Between anterior part of
the pericardium and posterior to the
sternum.
• Middle: Occupied by heart and its
vessels .
• Posterior: Between posterior part of
the heart and thoracic spine, extends
down behind posterior part of
diaphragm as it descends down.
Mediastinal mass
• A mediastinal mass does not
contain air bronchograms.
• The margins with the lung will
be obtuse.
• Disruption of mediastinal lines
(azygoesophageal recess,
anterior and posterior junction
lines).
• There can be associated spinal,
costal or sternal abnormalities.
Posterior mediastinal masses
› Cervicothoracic sign
› Widening of the paravertebral stripes
4Ts
HILUM OVERLAY SIGN
• To differentiate whether a hilar opacity
on a frontal chest radiograph is located
within the hilum or anterior/posterior to
it.
• Loss of normal pulmonary vessels
(interlobar artery, upper lobe arteries,
and left lower lobar artery) silhouette –
lesion from hilum. Causes of these
opacities include middle mediastinal
tumours, hilar adenopathy, pericardial
effusion, vascular enlargement,
and cardiac enlargement.
• Preserved hilar vessels implies the
cause of the opacity is not in contact
with the hilum and is, therefore, either
anterior or posterior to it. Most of these
opacities are masses in the anterior
mediastinum.
CERVICOTHORACIC SIGN
• Variation of the silhouette sign on
frontal chest radiography used to
determine whether a superior
(para)mediastinal soft tissue mass is
anterior or posterior to the trachea.
• As the anterior mediastinum ends at
the level of the clavicles, the upper
border of an anterior mediastinal
lesion cannot be visualised
extending above the clavicles. –
Positive cervicothoracic sign.
• Any lesions with a discernible upper
border above clavicular level must
be located posteriorly in the chest
(posterior mediastinum). – Negative
cervicothoracic sign.
PLEURA
• Serous membrane composed of
mesothelial cells and loose
connective tissue.
• Divided into parietal pleura and
visceral pleura.
• Contains up to 5 ml of fluid within
the two layers and normally not
separated.
• No communication between the
right and left pleural cavities.
Pleural opacities
• The most common condition is pleural
thickening.
• Differentiation between pulmonary and
extrapleural lesion is crucial in making
appropriate diagnosis.
Pulmonary lesion usually have acute
angles with the chest wall, are centered in
the lung, and engulf the pulmonary
vasculature.
A pleural opacity shows obtuse angles
with the lateral chest wall with tapered
margins, displaces the pulmonary
vasculature, changes its location on
respiration, and may show incomplete
border sign on chest radiograph
Extrapleural lesions may arise from
extrapleural fat, ribs, intercostal muscles,
and neurovascular bundle; cause erosion
of ribs.
Pleural effusion
• Presence of fluid in
the pleural space.
• It takes about 200-300 ml of
fluid before it comes visible on
an CXR. About 5 litres of pleural
fluid are present when there is
total opacification of the
hemithorax.
Transudate Exudate
Increased in hydrostatic pressure/
decreased capillary oncotic
pressure.
Seen in cases e.g.:
• cardia failure
• nephrotic syndrome
• cirrhosis
• trauma
• asbestos exposure
• post coronary artery bypass
grafting: small unilateral left-
sided pleural effusion can be
common
• certain medications: dasatinib
Increased in permeability of the
microcirculation or alteration in the
pleural space drainage to lymph
nodes.
Seen in cases e.g.:
• bronchial carcinoma
• secondary (metastatic)
malignancy
• pulmonary
embolism and infarction
• pneumonia
• tuberculosis
• mesothelioma
• rheumatoid arthritis
• systemic lupus erythematosus
(SLE)
• lymphoma
• Features on plain radiograph (erect)
 blunting of the costophrenic angle
 blunting of the cardiophrenic angle
 fluid within the horizontal or
oblique fissures
 eventually, a meniscus will be seen,
laterally and gently sloping
medially (however not visible in
case of hydropneumothorax )
 with large volume effusions,
mediastinal shift occurs away from
the effusion (however, if coexistent
collapse dominates then
mediastinal shift may occur towards
the effusion)
• Features on plain radiograph
(supine)
• no meniscus, and only a veil-like
increased density of the hemithorax
may be visible as the fluid collects
posteriorly
SUBPULMONIC EFFUSION
• Pleural effusion that collects
between the lung base and
diaphragm.
• Can only be seen on erect
radiograph:
• apparent elevation and
flattening of the diaphragm
(what appears to be the
diaphragm actually represents
the visceral pleura, and the true
diaphragm is obscured by the
presence of infrapulmonary fluid)
• peak of pseudodiaphragm lies
lateral to the normal position
• increased distance between the
pseudodiaphragm and the
gastric bubble (on the left).
Pleural plaques
• They have irregular shapes with
thickened nodular edge (holly leaf
appearance) and do not look like
a lung masses or consolidations.
• Bilateral and extensive in asbestos
related pleural plaques.
• Unilateral, calcified pleural
plaques seen in
• infection (TB)
• empyema
• hemorrhagic
Pneumothorax
• Presence of air in
the pleural space.
• Can be
• primary spontaneous: no
underlying lung disease
• secondary spontaneous:
underlying lung disease is
present
• iatrogenic/traumatic
Primary spontaneous Secondary spontaneous
Tall and thin people are more likely to
develop
There are well–known associations
• Marfan syndrome
• Ehlers-Danlos syndrome
• alpha-1-antitrypsin deficiency
• homocystinuria
Cystic lung disease
• bullae, blebs
• emphysema, asthma
• pneumocystis jiroveci pneumonia (PJP)
• honeycombing: end-stage interstitial
lung disease
• lymphangiomyomatosis (LAM)
• Langerhans cell histiocytosis (LCH)
• cystic fibrosis
Parenchymal necrosis
• lung abscess, necrotic
pneumonia, septic emboli, fungal
disease, tuberculosis
• cavitating neoplasm, metastatic
osteogenic sarcoma
• radiation necrosis
• pulmonary infarction
other
• catamenial pneumothorax: recurrent
spontaneous pneumothorax during
menstruation, associated
with endometriosis of pleura
• rarely pleuroparenchymal
fibroelastosis
Iatrogenic/traumatic
Iatrogenic:
• percutaneous biopsy
• barotrauma (e.g., divers), ventilator
• radiofrequency (RF) ablation of
lung mass
• endoscopic perforation of the
oesophagus
• central venous catheter insertion,
nasogastric tube placement
Trauma:
• pulmonary laceration (rib fracture)
• tracheobronchial rupture
• acupuncture 14,15
• oesophageal rupture
• On plain radiograph (erect) it
demonstrates
• visible visceral pleural edge is seen
as a very thin, sharp white line
• no lung markings are seen
peripheral to this line
• peripheral space is radiolucent
compared to the adjacent lung
• lung may completely collapse
• subcutaneous emphysema and
pneumomediastinum may also be
present
• Supine projection may only detect 50%
of the pneumothoraces. Signs include:
• relative lucency of the involved
hemithorax
• deep, sometimes tongue-like,
costophrenic sulcus: deep sulcus sign
• increased sharpness of the adjacent
mediastinal margin and diaphragm
• increased sharpness of the cardiac
borders or diaphragm
• visualisation of the anterior costophrenic
sulcus: double diaphragm sign
• visualisation of the inferior edge of the
collapsed lung above the diaphragm
• depression of the ipsilateral
hemidiaphragm
• Shift of mediastinum away from the
pneumothorax indicates tension
pneumothorax.

Chest xray pattern Part 1 Year 2 Class.pptx

  • 1.
  • 2.
    OUTLINE PATTERN RECOGNITION OFCHEST PATHOLOGY (X-RAY) • LUNG Increased density Decreased density • MEDIASTINUM • PLEURA & EXTRATHORACIC TUMOUR vs INFECTION
  • 3.
    Increased density (opacities) • Alveolar (consolidation) •Interstitial • Atelectasis (collapse) • Nodule or mass Decreased density (lucencies) • Cavitation • Cyst • Emphysema LUNG ABNORMALITIES ON CHEST X-RAY
  • 4.
  • 5.
    ALVEOLAR (CONSOLIDATION) • Resultsfrom pathologic process that fills the alveoli with fluid, pus, blood, cells (including tumor cells) or other substances. • General features on chest x-ray show ill-defined, fluffy, cottonwool-like appearance of airspace opacification causing obscuration of pulmonary vessels and air bronchograms.
  • 6.
    • Air bronchogram air-filledbronchi (dark) being made visible by the opacification of surrounding alveoli (grey/white).
  • 9.
    LOBAR CONSOLIDATION • Resultsfrom disease that starts in the periphery and spreads from one alveolus to another through the pores of Kohn. • At the borders of the disease some alveoli will be involved, while others are not, creating ill-defined borders. • As the disease reaches a fissure, this will result in a sharp delineation, since consolidation will not cross a fissure (limited by visceral pleura).
  • 11.
    BULGING FISSURE SIGN •Refers to lobar consolidation where the affected portion of the lung is expanded causing displacement of the adjacent fissure. • Classically, it has been described in right upper lobe (RUL) consolidation secondary to Klebsiella pneumonia. • Other causes include: • Infective (Strep. pneumoniae, Pseudomonas aeruginosa, Staph. aureus) • Lung adenocarcinoma • Lung abscess • Pulmonary haemorrhage
  • 12.
    DIFFUSE CONSOLIDATION • Progressionof multifocal opacities that coalesce produce diffuse consolidation. • Does not cross fissure.
  • 13.
    BATWING CONSOLIDATION • Bilateralperihilar distribution of consolidation. • The sparing of the periphery of the lung is attributed to a better lymphatic drainage in this area. • Most typical of pulmonary oedema, both cardiogenic and non-cardiogenic. • Sometimes it is seen in pneumonias.
  • 14.
    ATELECTASIS (COLLAPSE) • Resultof loss of air in a lung or part of the lung with subsequent volume loss due to airway obstruction or compression of the lung by pleural fluid or a pneumothorax. • General features on chest x-ray: • Sharply-defined opacity obscuring vessels without air-bronchogram. • Volume loss resulting in displacement of diaphragm, fissures, hila or mediastinum. Passive Loss of intrapleural negative pressure causing lung to be no longer held against chest wall. Obstructive Occurs as a result of complete obstruction of an airway. No new air can enter, any air that is already there is eventually absorbed into the pulmonary capillary system.
  • 15.
    Compressive atelectasis • occursas a result of any thoracic space-occupying lesion compressing the lung and forcing air out of the alveoli Cicatrization atelectasis • occurs as a result of scarring or fibrosis that reduces lung expansion • common aetiologies include granulomatous disease, necrotizing pneumonia and radiation fibrosis
  • 16.
    Right upper lobecollapse • increased density in the upper medial aspect of the right hemithorax • elevation and/or superior bowing of the horizontal fissure • loss of the normal right medial cardio-mediastinal contour • elevation of the right hilum • rotation of the bronchus intermedius laterally, appearing more horizontal than usual • hyperinflation of the right middle and lower lobe result in increased translucency of the mid and lower parts of the right lung • right juxtaphrenic peak (Kattan sign)
  • 17.
    GOLDEN S SIGN •Typically seen with right upper lobe collapse. • Created by a central mass obstructing the upper lobe bronchus and should raise suspicion of a primary bronchogenic carcinoma. • Can also be caused by other central masses, such as metastasis, primary mediastinal tumour, or enlarged lymph nodes.
  • 18.
    Right middle lobecollapse • right mid to lower zone air space opacification (which can be subtle) • the normal horizontal fissure is no longer visible (as it rotates inferiorly rendering it non- tangential to the x-ray beam) • obscuration of the right heart border • lateral projection: a triangular opacity in the anterior aspect of the chest overlying the cardiac shadow.
  • 19.
    Right lower lobecollapse • triangular opacity at the right lower zone (usually medially) with the apex pointing towards the right hilum • obscuration of the medial aspect of the dome of right hemidiaphragm • inferior displacement of the right hilum • descending interlobar pulmonary artery is not visible • preservation of a clear right heart border, which is contacted by the right middle lobe • inferior displacement of the horizontal fissure
  • 20.
    Left upper lobecollapse • Collapsed left upper lobe appears as a hazy or veiling opacity extending out from the left hilum and fading out inferiorly • Obscuration of parts of the normal cardiomediastinal contour particularly where the lingular segments abuts the left heart border • Luftsichel sign the hyperexpanded superior segment of the left lower lobe insinuates between the left upper lobe and the superior mediastinum, sharply silhouetting the aortic arch resulting in a sickle-shaped lucency medially • The left hilum is drawn upwards
  • 21.
    Left lower lobecollapse • triangular left lower zone opacification (usually medially, retrocardiac) with the apex pointing towards the left hilum • edge of the collapsed lung may create a 'double cardiac contour' • inferior displacement of the left hilum • Flat waist sign: flattening of the left heart border • obscuration of the left hemidiaphragm • obscuration of the descending aorta • preservation of a clear left heart border, which is contacted by the lingular segments of the left upper lobe • inferior displacement of the oblique fissure • descending interlobar pulmonary artery is not visible
  • 22.
    Plate atelectasis • Focalarea of subsegmental atelectasis that has a linear shape. • May appear to be horizontal, oblique or perpendicular line of 1-3 mm in thickness. • Frequently seen in patients in ICU due to poor ventilation and postoperative patients. • In most cases these findings have no clinical significance and are seen in smokers and elderly.
  • 23.
    SILHOUETTE SIGN • Pathologicalloss of two adjacent structures differentiation (i.e. lung and mediastinal border). • It denotes that a mediastinal border can only be obscured by pathology which is in direct anatomical contact. • Useful in localising areas of airspace opacities, atelectasis or mass within the lung. Loss of silhouette: • right paratracheal stripe: right upper lobe • right heart border: right middle lobe or medial right lower lobe • right hemidiaphragm: right lower lobe • aortic knuckle: left upper lobe • left heart border: lingular segments of the left upper lobe • left hemidiaphragm or descending aorta: left lower lobe
  • 24.
    INTERSTITIAL OPACITY • Reticularopacities or small nodules due to involvement of the supporting tissue of the lung parenchyma (interstitium). • Results from thickening of any of the interstitial compartments by blood, water, tumor, cells, fibrous disease or any combination thereof. • Can be reticular, reticulonodular, or linear where the predominant pattern is a result of the underlying pathological process.
  • 25.
    Reticular interstitial opacity •Complex network of curvilinear opacities that usually involved the lung diffusely. • Can be subdivided by their size based on the size of the lucent spaces created by the intersection of lines.
  • 26.
    • Fine "ground-glass"(1-2 mm): seen in processes that thicken the pulmonary interstitium to produce a fine network of lines, e.g. interstitial pulmonary oedema • Medium "honeycombing" (3-10 mm): commonly seen in pulmonary fibrosis with involvement of the parenchymal and peripheral interstitium • Coarse (>10 mm): cystic spaces caused by parenchymal destruction, e.g. usual interstitial pneumonia, pulmonary sarcoidosis, pulmonary Langerhans cell histiocytosis.
  • 28.
    Reticulonodular interstitial opacity •Overlap of reticular shadows or by the presence of reticular shadowing and pulmonary nodules. • Relatively common appearance on a chest radiograph, very few diseases are confirmed to show this pattern pathologically:  silicosis  pulmonary sarcoidosis  berylliosis  lymphangitic carcinomatosis  hepatopulmonary syndrome - basal  pneumocystis pneumonia  bronchocentric granulomatosis  pulmonary Langerhans cell histiocystosis  lymphocytic interstitial pneumonitis  Erdheim-Chester disease
  • 29.
    Linear interstitial opacity •Seen in processes that thicken the axial (bronchovascular) interstitium or the peripheral pulmonary interstitium. • Axial: diffuse thickening along the bronchovascular tree seen as parallel opacities radiating from the hila (seen transversely) or peribronchial cuffing (seen en face). • Peripheral: thickening of the peripheral interstitium (either medially or laterally) produces Kerley lines. • Axial interstitial thickening is difficult to distinguish from airways disease that result in bronchial wall thickening, (e.g. bronchiectasis, asthma) and most often seen in interstitial pulmonary oedema.
  • 30.
    Kerley lines (septallines) • Prominent interlobular septa in the pulmonary interstitium because of lymphatic engorgement or oedema of the connective tissues of the interlobular septa. • Usually occur when pulmonary capillary wedge pressure reaches 20-25 mmHg. Causes • pulmonary oedema • neoplasm • lymphangitic spread of cancer • breast cancer • colon cancer • stomach cancer • pancreatic cancer • lung cancer • lymphoma • pulmonary lymphoma • pneumonia • viral pneumonia • mycoplasma pneumonia • Pneumocystis pneumonia • interstitial pulmonary fibrosis • pneumoconiosis • sarcoidosis
  • 31.
    Kerley A • 2-6cm long oblique lines that are <1 mm thick and course towards the hila. • Represents thickening of the interlobular septa that contain lymphatic connections between the perivenous and bronchoarterial lymphatics deep within the lung parenchyma. • On chest radiographs they are seen to cross normal vascular markings and extend radially from the hilum to the upper lobes.
  • 32.
    Kerley B • Thinlines 1-2 cm in length in the periphery of the lung(s). • Represent thickened subpleural interlobular septa and are usually seen at the lung bases. • Perpendicular to the pleural surface and extend out to it. *Kerley D lines are exactly the same as Kerley B lines, except that they are seen on lateral chest radiographs in the retrosternal air gap.
  • 33.
    Kerley C • shortlines which do not reach the pleura and do not course radially away from the hila (neither A nor B).
  • 34.
    NODULES OR MASSES Suggestedrisk factors to consider include older age, heavy smoking, irregular or spiculated margins, and upper lobe location. • A discrete, well- marginated, rounded opacity less than or equal to 3 cm in diameter. • Lesions smaller than 3 cm are most commonly benign granulomas, while lesions larger than 3 cm are treated as malignancies until proven otherwise and are called masses.
  • 35.
    Metastases • Typically appearas peripheral, rounded nodules of variable size, scattered throughout both lungs predominantly lower lobes and subpleural.
  • 36.
    Mucoid impaction • Canmimic the appearance of lung nodules or a mass. • Commonly seen in patients with bronchiectasis, as in cystic fibrosis (CF), allergic bronchopulmonary aspergillosis (ABPA) and bronchial atresia. • ‘Finger-in-glove’ appearance: mucus in dilated bronchi looks like fingers in glove.
  • 37.
  • 38.
  • 39.
    Cavity • Frequently arisewithin a mass or an area of consolidation as a result of necrosis.
  • 40.
    Monod sign • Gasthat surrounds a mycetoma (most commonly an aspergilloma) in a pre- existing pulmonary cavity. • Gas around the mycetoma is often crescent-shaped and hence, the term air crescent sign is used interchangeably.
  • 41.
    Pneumatocele • Majority ofpneumatoceles occur as a result of pneumonia, most common causative agents being S. aureus.
  • 42.
    Bulla • Focal regionsof emphysema with no discernible wall which measure more than 1 or 2 cm in diameter. • Often subpleural in location and are typically larger in the apices
  • 43.
    Emphysema • Abnormal permanentenlargement of the airspaces distal to the terminal bronchioles accompanied by destruction of the alveolar wall and without obvious fibrosis. • Chest x-ray does not image emphysema directly, but indirect signs • hyperinflation • paucity of blood vessels • pulmonary arterial hypertension features (pruning of peripheral vessels, increased calibre of central arteries, right ventricular enlargement)
  • 44.
    MEDIASTINUM Mediastinal division • Superior:Above a line drawn from lower border of T4 to sternal angle. • Anterior: Between anterior part of the pericardium and posterior to the sternum. • Middle: Occupied by heart and its vessels . • Posterior: Between posterior part of the heart and thoracic spine, extends down behind posterior part of diaphragm as it descends down.
  • 45.
    Mediastinal mass • Amediastinal mass does not contain air bronchograms. • The margins with the lung will be obtuse. • Disruption of mediastinal lines (azygoesophageal recess, anterior and posterior junction lines). • There can be associated spinal, costal or sternal abnormalities.
  • 46.
    Posterior mediastinal masses ›Cervicothoracic sign › Widening of the paravertebral stripes 4Ts
  • 47.
    HILUM OVERLAY SIGN •To differentiate whether a hilar opacity on a frontal chest radiograph is located within the hilum or anterior/posterior to it. • Loss of normal pulmonary vessels (interlobar artery, upper lobe arteries, and left lower lobar artery) silhouette – lesion from hilum. Causes of these opacities include middle mediastinal tumours, hilar adenopathy, pericardial effusion, vascular enlargement, and cardiac enlargement. • Preserved hilar vessels implies the cause of the opacity is not in contact with the hilum and is, therefore, either anterior or posterior to it. Most of these opacities are masses in the anterior mediastinum.
  • 48.
    CERVICOTHORACIC SIGN • Variationof the silhouette sign on frontal chest radiography used to determine whether a superior (para)mediastinal soft tissue mass is anterior or posterior to the trachea. • As the anterior mediastinum ends at the level of the clavicles, the upper border of an anterior mediastinal lesion cannot be visualised extending above the clavicles. – Positive cervicothoracic sign. • Any lesions with a discernible upper border above clavicular level must be located posteriorly in the chest (posterior mediastinum). – Negative cervicothoracic sign.
  • 49.
    PLEURA • Serous membranecomposed of mesothelial cells and loose connective tissue. • Divided into parietal pleura and visceral pleura. • Contains up to 5 ml of fluid within the two layers and normally not separated. • No communication between the right and left pleural cavities.
  • 50.
    Pleural opacities • Themost common condition is pleural thickening. • Differentiation between pulmonary and extrapleural lesion is crucial in making appropriate diagnosis. Pulmonary lesion usually have acute angles with the chest wall, are centered in the lung, and engulf the pulmonary vasculature. A pleural opacity shows obtuse angles with the lateral chest wall with tapered margins, displaces the pulmonary vasculature, changes its location on respiration, and may show incomplete border sign on chest radiograph Extrapleural lesions may arise from extrapleural fat, ribs, intercostal muscles, and neurovascular bundle; cause erosion of ribs.
  • 53.
    Pleural effusion • Presenceof fluid in the pleural space. • It takes about 200-300 ml of fluid before it comes visible on an CXR. About 5 litres of pleural fluid are present when there is total opacification of the hemithorax. Transudate Exudate Increased in hydrostatic pressure/ decreased capillary oncotic pressure. Seen in cases e.g.: • cardia failure • nephrotic syndrome • cirrhosis • trauma • asbestos exposure • post coronary artery bypass grafting: small unilateral left- sided pleural effusion can be common • certain medications: dasatinib Increased in permeability of the microcirculation or alteration in the pleural space drainage to lymph nodes. Seen in cases e.g.: • bronchial carcinoma • secondary (metastatic) malignancy • pulmonary embolism and infarction • pneumonia • tuberculosis • mesothelioma • rheumatoid arthritis • systemic lupus erythematosus (SLE) • lymphoma
  • 54.
    • Features onplain radiograph (erect)  blunting of the costophrenic angle  blunting of the cardiophrenic angle  fluid within the horizontal or oblique fissures  eventually, a meniscus will be seen, laterally and gently sloping medially (however not visible in case of hydropneumothorax )  with large volume effusions, mediastinal shift occurs away from the effusion (however, if coexistent collapse dominates then mediastinal shift may occur towards the effusion)
  • 55.
    • Features onplain radiograph (supine) • no meniscus, and only a veil-like increased density of the hemithorax may be visible as the fluid collects posteriorly
  • 56.
    SUBPULMONIC EFFUSION • Pleuraleffusion that collects between the lung base and diaphragm. • Can only be seen on erect radiograph: • apparent elevation and flattening of the diaphragm (what appears to be the diaphragm actually represents the visceral pleura, and the true diaphragm is obscured by the presence of infrapulmonary fluid) • peak of pseudodiaphragm lies lateral to the normal position • increased distance between the pseudodiaphragm and the gastric bubble (on the left).
  • 57.
    Pleural plaques • Theyhave irregular shapes with thickened nodular edge (holly leaf appearance) and do not look like a lung masses or consolidations. • Bilateral and extensive in asbestos related pleural plaques. • Unilateral, calcified pleural plaques seen in • infection (TB) • empyema • hemorrhagic
  • 58.
    Pneumothorax • Presence ofair in the pleural space. • Can be • primary spontaneous: no underlying lung disease • secondary spontaneous: underlying lung disease is present • iatrogenic/traumatic Primary spontaneous Secondary spontaneous Tall and thin people are more likely to develop There are well–known associations • Marfan syndrome • Ehlers-Danlos syndrome • alpha-1-antitrypsin deficiency • homocystinuria Cystic lung disease • bullae, blebs • emphysema, asthma • pneumocystis jiroveci pneumonia (PJP) • honeycombing: end-stage interstitial lung disease • lymphangiomyomatosis (LAM) • Langerhans cell histiocytosis (LCH) • cystic fibrosis Parenchymal necrosis • lung abscess, necrotic pneumonia, septic emboli, fungal disease, tuberculosis • cavitating neoplasm, metastatic osteogenic sarcoma • radiation necrosis • pulmonary infarction other • catamenial pneumothorax: recurrent spontaneous pneumothorax during menstruation, associated with endometriosis of pleura • rarely pleuroparenchymal fibroelastosis Iatrogenic/traumatic Iatrogenic: • percutaneous biopsy • barotrauma (e.g., divers), ventilator • radiofrequency (RF) ablation of lung mass • endoscopic perforation of the oesophagus • central venous catheter insertion, nasogastric tube placement Trauma: • pulmonary laceration (rib fracture) • tracheobronchial rupture • acupuncture 14,15 • oesophageal rupture
  • 59.
    • On plainradiograph (erect) it demonstrates • visible visceral pleural edge is seen as a very thin, sharp white line • no lung markings are seen peripheral to this line • peripheral space is radiolucent compared to the adjacent lung • lung may completely collapse • subcutaneous emphysema and pneumomediastinum may also be present
  • 60.
    • Supine projectionmay only detect 50% of the pneumothoraces. Signs include: • relative lucency of the involved hemithorax • deep, sometimes tongue-like, costophrenic sulcus: deep sulcus sign • increased sharpness of the adjacent mediastinal margin and diaphragm • increased sharpness of the cardiac borders or diaphragm • visualisation of the anterior costophrenic sulcus: double diaphragm sign • visualisation of the inferior edge of the collapsed lung above the diaphragm • depression of the ipsilateral hemidiaphragm • Shift of mediastinum away from the pneumothorax indicates tension pneumothorax.

Editor's Notes

  • #10 The most common cause for lobar consolidation is pneumonia.
  • #16 Kattan sign-peaked or tented appearance of a hemidiaphragm which can occur in the setting of lobar collapse or post lobectomy (lung). It is caused by retraction of the lower end of diaphragm at an inferior accessory fissure (most common 1), major fissure or inferior pulmonary ligament. It is commonly seen in collapse of the left or right upper lobes but may also be seen in middle lobe collapse.